LDC
in MIMO Ricean Channels: Optimal transmit strategy with MMSE detection
Abstract:
In this paper, we study a MIMO system with a transmitter using a linear
dispersion code (LDC) and a linear minimum
mean square-error (MMSE) detector at the receiver in a Ricean
flat-fading environment. We assume that the receiver has perfect
channel state information and the transmitter knows only the mean
channel matrix either by feedback or channel estimation. The focus
of our work is the analysis of the optimal transmit strategy using
different types of LDC. On the one hand, we consider spatial mul-
tiplexing schemes that achieve high data rates, but sacrifice diversity.
On the other hand, we have schemes that achieve full diver-
sity like quasi-orthogonal space-time block codes or orthogonal
space-time block code. Depending on the LDC in use, the opti-
mization problem is either convex or nonconvex. For both of these
classes of LDC, we first derive the properties of the average nor-
malizedMSE and then analyze the impact of the mean component on the
MSE, the optimal transmit strategy and the optimal power
allocation. Finally, we derive some bounds on the error rate
performance for different scenarios with the MMSE receiver.
